If you're in a long-term relationship, you probably don't follow Scareltt Johansson's advice to get tested for STDs twice a year. Why should you bother? One woman tells a cautionary tale

I have slept with a grand total of four men. There were two distant teenage encounters, then I fell in love with Joe at university at the age of 20 and we married two years later. Regrettably, there has since been another; let’s call him Mr X. In fact, I have to call him Mr X, because although his face is burnt into my memory, I can’t remember his name.

My sister’s wedding was set for August 2004. A few weeks earlier, a group of us flew to Dublin for a big girlie hen night. At the time, I was working part-time as a solicitor, in between ferrying my daughters (then two and four) to nursery, ballet, swimming and play dates. I’d never left the girls overnight before, but the prospect of staying at the Clarence hotel with Katie and her friends — she’s seven years younger than me and works